Population growth, externalities, and poverty

The authors review the implications for social policy in developing countries of two major justifications for fertility reduction: the externality argument and the income redistribution argument. First they set out the arguments. In terms of how policy affects the poor, they show that the implications of the two different arguments are virtually identical. Both imply that the only reasonable way to view policies to reduce fertility is as activities in which one segment of society (the rich) is offering another segment (the poor) compensation to elicit a change in behavior. Where there are true externalities, the rich may also end up as well or better off in terms of income than they were, because everyone can benefit from the overall efficiency gain. Where there are not true externalities, the poor are made better off in the sense of real income while the rich gain in terms of utility by financing the necessary social programs. The authors outline briefly the program implications of this welfare approach: more emphasis on a package of targeted social programs, and more emphasis in family planning services on client welfare and contraceptive choice.Health Monitoring&Evaluation,Environmental Economics&Policies,Economic Theory&Research,Adolescent Health,Gender and Social Development

Fuel containment, lightning protection and damage tolerance in large composite primary aircraft structures

The damage-tolerance characteristics of high strain-to-failure graphite fibers and toughened resins were evaluated. Test results show that conventional fuel tank sealing techniques are applicable to composite structures. Techniques were developed to prevent fuel leaks due to low-energy impact damage. For wing panels subjected to swept stroke lightning strikes, a surface protection of graphite/aluminum wire fabric and a fastener treatment proved effective in eliminating internal sparking and reducing structural damage. The technology features developed were incorporated and demonstrated in a test panel designed to meet the strength, stiffness, and damage tolerance requirements of a large commercial transport aircraft. The panel test results exceeded design requirements for all test conditions. Wing surfaces constructed with composites offer large weight savings if design allowable strains for compression can be increased from current levels

Composite transport wing technology development: Design development tests and advanced structural concepts

Numerous design concepts, materials, and manufacturing methods were investigated for the covers and spars of a transport box wing. Cover panels and spar segments were fabricated and tested to verify the structural integrity of design concepts and fabrication techniques. Compression tests on stiffened panels demonstrated the ability of graphite/epoxy wing upper cover designs to achieve a 35 percent weight savings compared to the aluminum baseline. The impact damage tolerance of the designs and materials used for these panels limits the allowable compression strain and therefore the maximum achievable weight savings. Bending and shear tests on various spar designs verified an average weight savings of 37 percent compared to the aluminum baseline. Impact damage to spar webs did not significantly degrade structural performance. Predictions of spar web shear instability correlated well with measured performance. The structural integrity of spars manufactured by filament winding equalled or exceeded those fabricated by hand lay-up. The information obtained will be applied to the design, fabrication, and test of a full-scale section of a wing box. When completed, the tests on the technology integration box beam will demonstrate the structural integrity of an advanced composite wing design which is 25 percent lighter than the metal baseline

A pollen profile from Reed bog, Randolph County, Indiana

Sediments from lakes and bogs have given valuable records which indicate succession of forests and climatic changes since glacial retreat at the close of Pleistocene times in the geographical area now known as Indiana. The closing chapter of this history has, however, not yet been written, for every pollen profile adds new discoveries of variations in forest composition which may be due to difference in geographical location or to microclimatic variations. Thus, we might consider each new bog record a contribution toward reconstruction of forests of the past which covered the soils of Indiana. There are, especially, many unanswered questions with respect to forest succession along the line of junction between Early and Late Wisconsin glaciation in Indiana. Into this picture we fit the study of the pollen records from Reed bog where today corn fields mark the culmination of great vegetational changes which ranged from coniferous to primarily broad leaved forests

Pollen Analysis of a Peat Deposit in Livingston County, Illinois

This study essays to compare, and in some degree to supplement, pollen analyses thus far published for Illinois. Even though results of studies of fossil pollens seem very similar, each pollen profile is individual and varies in many details from all other profiles. For this reason, each new analysis is more than a repetition of what has already been studied and reported; it is a possible verification of these previous studies and a valuable supplement to the growing science of pollen analysis. It is hoped that the preliminary study of fossil diatom valves found in this deposit can be correlated with the fossil pollen record, and possibly reveal valuable additional data in the quest for information on the history of the pond and of climates of its vicinity

Relationship of feed intake during various portions of the lactation to total intake in dairy cattle

Since the cows\u27 ability to consume feed is a limiting factor on milk production, the development of alternatives to the measurement of complete feed intake are necessary if this trait is to be measured and evaluated on large numbers of animals. The purpose of this research was to examine the part-to-whole relationships of lactation feed intake to determine if suitable alternatives were available. Feed intake data on 225 first lactations of daughters of 13 sires fed two rations were used to study the part-to-whole relationships of lactation feed intake. Correlations were used to determine the relation-ship of feed intake in various portions of the lactation with the total feed intake for the lactation. From this study it appears that feed intake during shorter periods in the middle of the lactation are as accurate as extended periods at the beginning of the lactation as a measurement for estimating total feed intake. Ratio factors were calculated from which lactation estimated net energy intake can be predicted from intake during a portion of the lactation. The similarity of the ratio factors between the two rations, in mid-lactation, suggests that this information may be applied to a wide range of management levels and could probably be used to obtain reasonable estimates of means for older animals

A study of abundance of stems per acre in relation to age of stand

Of the great numbers of seeds and spores which are produced annually by the plant kingdom, only a relatively small number germinate, and fewer still are able to withstand the tremendous competition for light, soil moisture, nutrients, etc. Only a small number of seedlings are able to ecese. Weaver and Clements (8) state that competition in effecting the supply of water and light is most decisive during the development of the seedling and at the time of reproduction, particularly among perennials and woody plants. Accordingly it plays a large part in determining the number of occupants and of invaders in an area in each stage of a sere and thus in helping to control the course of development

News in Cyberspace: The Creation of the New Ignorance

Computers are dummying us down. Book learning has given way to computer speak. Modern technology overwhelms us. Users are enthralled with gadgets to the point where they have lost themselves in them. We have abandoned, perhaps mislaid, our sense for ignorance; what it means to be illiterate in the 21st century; and working definitions for truth. In this environment a dab of education (enough to make somebody lethal), a sprinkle of bigotry, and fear produce people with ideas that are bad for us. This essay cautions against trucking with those folk; it marks what they do in the media that is unhealthy for us; and fixes what\u27s broken in information dispensaries (e. g., broadcasting, film and blogs) so future users won\u27t have to bother with this stuff